Toxicity of hexanic and methanolic fractions from copaifera reticulata ducke (Leguminosae – Caesalpinoidea) against Aedes aegypti Linnaeus (Diptera – Culicidae), in field assays

v. 45, n. 2, abr./jun. 2016.

Exploring Relationships Between Vector-Borne Diseases and Landscape Architecture: Aedes aegypti, Aedes albopictus and Landscape Architecture

Thesis (Master's)--University of Washington, 2016-06

Impactos multifactoriales del cambio climático en Nicaragua y estrategias de adaptación

En Nicaragua, el cambio climático está asociado al fenómeno de El Niño y La Niña, que en situaciones extremas tienen efectos económicos, sociales y ambientales fatales. El fenómeno de El Niño es una condición anómala en la temperatura del océano pacifico tropical del este. Ocurre cuando el agua del océano pacifico ecuatorial se hace más caliente que el promedio (1°C - 3°C).Cuando esto sucede, la atmosfera encima del océano también reacciona. Ese cambio de temperatura afecta la circulación del viento reduciendo considerablemente las lluvias(Cruz Roja Nicaragüense, 2014). Este calentamiento de las aguas sucede cada dos o siete años y puede durar entre 12 y 18 meses. Según los cambios en el clima así se comporta ElNiño y puede ser clasificado como débil o moderado, pero también como fuerte o muy fuerte, en estos últimos casos provocando sequías extremas. Cuando estas aguas se enfrían sucede lo contrario, llueve mucho y hay inundaciones, y se le llama La Niña. Los huracanes más destructivos ocurren en periodos de La Niña, observados en el océano atlántico, Mar Caribe y Golfo de México. Estos favorecen epidemias transmitidas por el mosquito Aedes aegyti, como el dengue, la malaria y recientemente el Chikungunya, así como la leptospirosis (enfermedad bacteriana que se trasmite por consumo de agua y alimentos contaminados con orina de roedores), deslizamientos de tierra, pérdidas humanas, pérdidas de la infraestructura social y productiva, tanto pública como privada (escuelas, caminos,carreteras, puentes, viviendas, cercados, corrales, etc.).En síntesis, fenómenos extremos de El Niño o La Niña provocan un fuerte deterioro de los medios de vida de la población de las zonas afectadas, que dependen de los recursos agua, suelo, bosque y del clima.

Diagnóstico laboratorial de casos de importação de infeções por vírus Zika

O vírus Zika (Flavivirus) é um arbovírus transmitido sobretudo por mosquitos, mas também, por transmissão materno-fetal e sexual. Existem evidências que as infeções por vírus Zika podem estar associadas à síndrome de Guillian-Barré e a casos congénitos de microcefalia e outras malformações do sistema nervoso central. As infeções por vírus Zika, Dengue e Chikungunya partilham, atualmente, os mosquitos vetores, a sintomatologia e a distribuição geográfica. O Centro de Estudos de Vetores e Doenças Infeciosas do Instituto Nacional de Saúde Doutor Ricardo Jorge no seu Laboratório Nacional de Referência de Vírus Transmitidos por Vetores tem desenvolvido o diagnóstico e estudos epidemiológicos de vírus transmitidos por artrópodes desde o princípio dos anos 90. O diagnóstico de Zika foi desenvolvido e padronizado em 2007. O laboratório desenvolveu testes de diagnóstico molecular e serológico tendo identificado vários casos de importação para o território português e feito o diagnóstico diferencial com Dengue e Chikungunya e o despiste de infeção em grávidas e em casos de transmissão sexual.

Isolamento de uma quitinase extraída do cefalotórax do camarão marinho Litopenaeus schmitti (BURKENROAD, 1936) : avaliação de suas atividades antimicrobiana e larvicida

Chitinases are enzymes involved in degradation of chitin and are present in a range of organisms, including those that do not contain chitin, such as bacteria, viruses, plants and animals, and play important physiological and ecological roles. Chitin is hydrolyzed by a chitinolytic system classified as: endo-chitinases, exo-chitinases and N-acetyl-b-D-glucosaminidases. In this study a Litochitinase1 extracted from the cephalotorax of the shrimp Litopenaeus Schmitt was purified 987.32 times using ionexchange chromatography DEAE-Biogel and molecular exclusion Sephacryl S-200. These enzyme presented a molecular mass of about 28.5 kDa. The results, after kinetic assay with the Litochitinase1 using as substrate p-nitrophenyl-N-acetyl-b-Dglucosaminideo, showed apparent Km of 0.51 mM, optimal activity at pH ranging from 5.0 to 6.0, optimum temperature at 55°C and stability when pre-incubated at temperatures of 25, 37, 45, 50 and 55°C. The enzyme showed a range of stability at pH 4.0 to 5.5. HgCl2 inhibited Litochitinase1 while MgCl2 enhances its activity. Antimicrobial tests showed that Litochitinase1 present activity against gram-negative bacterium Escherichia coli in the 800 μg/mL concentration. The larvicidal activity against Aedes aegypti was investigated using crude extracts, F-III (50-80%) and Litochitinase1 at 24 and 48 hours. The results showed larvicidal activity in all these samples with EC50 values of 6.59 mg/mL for crude extract, 5.36 mg/mL for F-III and 0.71 mg/mL for Litochitinase1 at 24 hours and 3.22 and 0.49 mg/mL for the F-III and Litochitinase1 at 48 hours, respectively. Other experiments confirmed the presence of chitin in the midgut of Aedes aegypti larvae, which may be suffering the action of Litochitinase1 killing the larvae, but also the absence of contaminating proteins as serine proteinase inhibitors and lectins in the crude extract, F-III and Litochitinase1, indicating that the death of the larvae is by action of the Litochitinase1. We also observed that the enzymes extracted from intestinal homogenate of the larvae no have activity on Litochitinase1. These results indicate that the enzyme can be used as an alternative to control of infections caused by Escherichia coli and reducing the infestation of the mosquito vector of dengue.

Un modelo tipo predador - presa para la dinámica de población del mosquito Aedes aegypti con control químico y control biológico

Según la Organización Mundial de la Salud (OMS, 2000) la fiebre por dengue y la fiebre hemorrágica 1 por dengue son un problema de salud pública a las cuales dos quintas partes de la población mundial se encuentran en riesgo. Las principales medidas de prevención y control han sido la fumigación masiva de insecticidas dirigida contra los mosquitos adultos (adulticidas) y la aplicación de larvicidas (control químico). Sin embargo, a pesar de que dichas medidas reducen rápidamente la población de mosquitos adultos y eliminan un 90% de la población de larvas en un criadero, su efecto es sólo transitorio pues no afectan la generación de nuevos mosquitos. En efecto, los registros estadísticos demuestran un avance del mosquito a pesar de las campañas de fumigación y aplicación de larvicidas (OMS, 2000). Por otra parte Hernández y García (2000) señalan que hay factores negativos asociados con el control químico de las poblaciones de mosquitos.

Spatial and temporal country-wide survey of temephos resistance in Brazilian populations of Aedes aegypti

The organophosphate temephos has been the main insecticide used against larvae of the dengue and yellow fever mosquito ( Aedes aegypti ) in Brazil since the mid-1980s. Reports of resistance date back to 1995; however, no systematic reports of widespread temephos resistance have occurred to date. As resistance investigation is paramount for strategic decision-making by health officials, our objective here was to investigate the spatial and temporal spread of temephos resistance in Ae. aegypti in Brazil for the last 12 years using discriminating temephos concentrations and the bioassay protocols of the World Health Organization. The mortality results obtained were subjected to spatial analysis for distance interpolation using semi-variance models to generate maps that depict the spread of temephos resistance in Brazil since 1999. The problem has been expanding. Since 2002-2003, approximately half the country has exhibited mosquito populations resistant to temephos. The frequency of temephos resistance and, likely, control failures, which start when the insecticide mortality level drops below 80%, has increased even further since 2004. Few parts of Brazil are able to achieve the target 80% efficacy threshold by 2010/2011, resulting in a significant risk of control failure by temephos in most of the country. The widespread resistance to temephos in Brazilian Ae. aegypti populations greatly compromise effective mosquito control efforts using this insecticide and indicates the urgent need to identify alternative insecticides aided by the preventive elimination of potential mosquito breeding sites.

Robot acuático hidrostático espectral de rayos laser, para el control larvario de mosquitos de importancia médica en Salud Pública.

Diseñar y construir un robot acuático que destruya la presencia de larvas o pupas de mosquitos en contenedores de agua. Se construyó y se diseñó un robot con materiales reciclables construido con tubos de cañería PVC, lupa, sensores de luz y barrera, motor de fuente 110 v, resistencias, LCR, cargador 9 v y focos led, para que destruya larvas de mosquitos en un contenedor de agua. Como resultado hay una cero prevalencia de índice larvario porque el robot detecta presencia larvaria con sensores y rayos laser activándose automáticamente con el efecto de succión y destrucción larvas en su interior eliminándolas desechas al utilizar filtros de 10 micras y aspas metálicas, el robot se activa por cinco a diez minutos y se apaga automáticamente hasta esperar la alarma otra vez según disposición de larvas. Conclusión el uso del robot acuático en contenedores de agua no se encuentra índices larvarios, así como pupas, que puede ser utilizado como control antilarvario para el combate transmisor de Dengue, Zika, Chikungunya entre otros.
Design and build an aquatic robot to destroy the presence of larvae or pupae of mosquitoes in water containers. It was built and a robot with recyclables built with tubes pipe PVC, magnifier, light sensors and barrier, engine power 110 v, resistors, LCR, charger 9 vy spotlights led, to destroy mosquito larvae was designed in a container of water. As a result there is a zero prevalence Larval rate because the robot detects larval presence sensors and lasers automatically activated with the suction effect and larvae destruction their killing the inner cast off using filters of 10 microns and metal blades, the robot is activated by five to ten minutes to wait automatically turns off the alarm again available as larvae. Conclusion use water in water containers robot is not larval indices and pupae, which can be used as anti larval control for transmitter combat Dengue, Zika, Chikungunya among others.

Potencial larvicida de extratos de plantas regionais no controle de larvas de Aedes Aegypti (Diptera:Culicidae)

Dengue, amongst the virus illnesses one can get by vectorial transmission, is the one that causes more impact in the morbidity and mortality of world s population. The resistance to the insecticides has caused difficulties to control of vector insect (Aedes aegypti) and has stimulated a search for vegetables with larvicidal activity. The biodiversity of Caatinga is barely known and it is potential of use even less. Some plants of this biome are commercialized in free fairs northeast of Brazil, because of its phytotherapics properties. The vegetables in this study had been selected by means of a questionnaire applied between grass salesmen and natives of the Serido region from Rio Grande do Norte state; culicids eggs had been acquired with traps and placed in container with water for the larva birth. Thirty larvae had been used in each group (a group control and five experimental groups), with four repetitions four times. The vegetables had been submitted to the processes of decoction, infusion and maceration in the standard concentration of 100g of the vegetable of study in 1l of H2O and analyzed after ½, 1, 2, 4, 8, 12, 24 and 48 hours for verification of the average lethal dose (LD50) from the groups with thirty larva. The LD50 was analyzed in different concentrations (50g/l, 100g/l, 150g/l, 200g/l e 300g/l) of Aspidosperma pyrifolium Mart. 48 extracts of rind, leaf and stem of the seven vegetal species: Aspidosperma pyrifolium Mart., Mimosa verrucosa Benth, Mimosa hostilis (Mart.) Benth., Myracrodruon urundeuva Allemão, Ximenia americana L, Bumelia sartorum Mart Zizyphus joazeiro Mart, had been analyzed. The extracts proceeding from the three methods were submitted to the freezedrying, to evaluate and to quantify substances extracted in each process. The results had shown that Aspidosperma pyrifolium Mart. and Myracrodruon urundeuva Allemão are the species that are more distinguished as larvicidal after 24 hours of experiment, in all used processes of extraction in the assays. The Zizyphus joazeiro Mart species has not shown larvicidal activity in none of the assays. In relation to the extraction method, the decoction was the most efficient method in the mortality tax of the A. aegypti larvae

Aedes aegypti Pharate First Instar Aseasonal Quiescence Cues Anticipatory Plasticity with Implications for Urban Vector Ecology and Control

The eggs of the dengue fever vector Aedes aegypti possess the ability to undergo an extended quiescence period hosting a fully developed first instar larvae within its chorion. As a result of this life history stage, pharate larvae can withstand months of dormancy inside the egg where they depend on stored reserves of maternal origin. This adaptation known as pharate first instar quiescence, allows A. aegypti to cope with fluctuations in water availability. An examination of this fundamental adaptation has shown that there are trade-offs associated with it. Aedes aegypti mosquitoes are frequently associated with urban habitats that may contain metal pollution. My research has demonstrated that the duration of this quiescence and the extent of nutritional depletion associated with it affects the physiology and survival of larvae that hatch in a suboptimal habitat; nutrient reserves decrease during pharate first instar quiescence and alter subsequent larval and adult fitness. The duration of quiescence compromises metal tolerance physiology and is coupled to a decrease in metallothionein mRNA levels. My findings also indicate that even low levels of environmentally relevant larval metal stress alter the parameters that determine vector capacity. My research has also demonstrated that extended pharate first instar quiescence can elicit a plastic response resulting in an adult phenotype distinct from adults reared from short quiescence eggs. Extended pharate first instar quiescence affects the performance and reproductive fitness of the adult female mosquito as well as the nutritional status of its progeny via maternal effects in an adaptive manner, i.e., anticipatory phenotypic plasticity results as a consequence of the duration of pharate first instar quiescence and alternative phenotypes may exist for this mosquito with quiescence serving as a cue possibly signaling the environmental conditions that follow a dry period. M findings may explain, in part, A. aegypti’s success as a vector and its geographic distribution and have implications for its vector capacity and control.

2016 Chikungunya Virus Cases

After the bite of an infected mosquito, onset of illness occurs usually between 4 and 8 days, but can range from 2 to 12 days. Chikungunya is characterized by an abrupt onset of fever frequently accompanied by joint pain. Other common signs and symptoms include muscle pain, headache, nausea, fatigue and rash. The joint pain is often very debilitating, but usually lasts for a few days or may be prolonged to weeks. Hence the virus can cause acute, subacute, or chronic disease. Most patients recover fully, but in some cases joint pain may persist for several months, or even years. Occasional cases of eye, neurological, and heart complications have been reported, as well as gastrointestinal complaints. Serious complications are not common, but in older people, the disease can contribute to the cause of death. Often symptoms in infected individuals are mild and the infection may go unrecognized, or be misdiagnosed in areas where dengue occurs. Co-infections of dengue and chikungunya can occur.

“Biomarkers in a One Health perspective: current knowledge of their ability to merge human and animal health

Biomarkers are nowadays essential tools to be one step ahead for fighting disease, enabling an enhanced focus on disease prevention and on the probability of its occurrence. Research in a multidisciplinary approach has been an important step towards the repeated discovery of new biomarkers. Biomarkers are defined as biochemical measurable indicators of the presence of disease or as indicators for monitoring disease progression. Currently, biomarkers have been used in several domains such as oncology, neurology, cardiovascular, inflammatory and respiratory disease, and several endocrinopathies. Bridging biomarkers in a One Health perspective has been proven useful in almost all of these domains. In oncology, humans and animals are found to be subject to the same environmental and genetic predisposing factors: examples include the existence of mutations in BR-CA1 gene predisposing to breast cancer, both in human and dogs, with increased prevalence in certain dog breeds and human ethnic groups. Also, breast feeding frequency and duration has been related to a decreased risk of breast cancer in women and bitches. When it comes to infectious diseases, this parallelism is prone to be even more important, for as much as 75% of all emerging diseases are believed to be zoonotic. Examples of successful use of biomarkers have been found in several zoonotic diseases such as Ebola, dengue, leptospirosis or West Nile virus infections. Acute Phase Proteins (APPs) have been used for quite some time as biomarkers of inflammatory conditions. These have been used in human health but also in the veterinary field such as in mastitis evaluation and PRRS (porcine respiratory and reproductive syndrome) diagnosis. Advantages rely on the fact that these biomarkers can be much easier to assess than other conventional disease diagnostic approaches (example: measured in easy to collect saliva samples). Another domain in which biomarkers have been essential is food safety: the possibility to measure exposure to chemical contaminants or other biohazards present in the food chain, which are sometimes analytical challenges due to their low bioavailability in body fluids, is nowadays a major breakthrough. Finally, biomarkers are considered the key to provide more personalized therapies, with more efficient outcomes and fewer side effects. This approach is expected to be the correct path to follow also in veterinary medicine, in the near future.

GEOTECNOLOGIAS APLICADA AO MONITORAMENTO DO VETOR AEDES AEGYPTI NA ÁREA ITAQUI-BACANGA, SÃO LUIS - MA.

O uso do SIG na espacialização de dados referentes à saúde é de extrema importância para o monitoramento das variáveis relacionadas à doença em questão, como por exemplo, fatores físicos, sociais e variantes relacionadas ao vetor transmissor. Esta geotecnologia possui uma linguagem computacional, na qual é possível armazenar, cruzar e relacionar dados, através da localização de pontos na superfície terrestre. No Brasil, a problemática da dengue, diante do seu agravamento e a iminência de uma epidemia de proporções consideráveis, tem intensificado as pesquisas para o desenvolvimento de métodos mais eficazes para o controle dessa doença no ambiente urbano. Em nível local, a utilização de SIGs para o monitoramento da dengue no município de São Luís, contribuiu para uma análise da distribuição espacial da doença na cidade. Deste modo, esta pesquisa objetivou analisar o problema da dengue na referida localidade, utilizando as geotecnologias e a educação ambiental sinergicamente associadas, como estratégia para que a comunidade descobrisse, através da participação nas atividades da pesquisa, a dimensão do problema da dengue no seu próprio habitat.